Ignition switches

ABSTRACT

In an ignition switch for use in combination with a key operated steering column lock for a road vehicle, a movable contact member is mounted on a rotor for rotation with the rotor within the switch casing. First and second movable contact arms are carried by the rotor and are engageable with the contact member. Cooperating cam means on the casing of the switch and the first and second contact arms control engagement of the first and second contact arms with the contact member during rotation of the rotor relative to the casing, the first and second contact arms and the contact member defining the movable contacts of the switch.

iJite States atent Heap [54] IGNITIGN SWITCHES [72] Inventor: Alec John Heap, 18 Brunshaw Ave.,

Burnley, Lancashire, England [73] Assignee: Joseph Lucas (Industries) Limited,

Birmingham, England 22 Filed: Jan. 13,1971

21 Appl.No.: 106,018

UNITED STATES PATENTS Schwarze ..200/44 Arendt ..200/44 FOREIGN PATENTS OR APPLICATIONS 1,131,465 '6/1962 Germany ..200/44 [4 1 Aug. 8, 1972 1,160,140 7/1969 Great Britain ..200/44 Primary ExaminerRobert K. Schaefer Assistant Examiner-William J. Smith Attorney-l-lolman & Stern [57] ABSTRACT In an ignition switch for use in combination with a key operated steering column lock for a road vehicle, a movable contact member is mounted on a rotor for rotation with the rotor within the switch casing. First and second movable contact arms are carried by the rotor and are engageable with the contact member. Co-operating cam means on the casing of the switch and the first and second contact arms control engagement of the first and second contact arms with the contact member during rotation of the rotor relative to the casing, the first and second contact arms and the contact member defining the movable contacts of the switch.

3 Claims, 8 Drawing Figures PATENTEDAUB 8 m2 SHEET 1 BF 2 INVENTOR flan/oh; mam) 5% ATTORNEYS PATENTEDA B 8 I972 3.683.133

SHEET 2 or 2 INVENTOR rr ATTORNEYS IGNITION SWITCHES This invention relates to ignition switches for use in combination with key operated steering column locks for road vehicles, the switches being of the kind comprising a casing including a base at one end thereof, a plurality of fixed contacts on the base, a rotor rotatable within the casing, and movable contacts carried by said rotor, said movable contacts being engageable with certain of the fixed contacts in predetermined angular positions of said rotor to complete electrical circuits between said fixed contacts.

According to the invention an ignition switch of the kind specified includes a movable contact member mounted on the rotor for rotation therewith, first and second movable contact arms carried by the rotor and engageable with the contact member, and co-operating cam means on the casing of the switch and said first and second contact arms, said cam means controlling engagement of the first and second contact arms with the contact member during rotation of the rotor relative to the casing, and said first and second contact arms and said contact member defining the movable contacts of the switch.

In the accompanying drawings,

FIG. 1 is a sectional view of a switch in accordance with one example of the invention,

FIG. 2 is a sectional view along line A-A in FIG. 1,

FIG. 3 is a sectional view along line B-B in FIG. 1, and

FIG. 4 is a diagrammatic representation of the operating positions of the switch shown in FIG. 1.

Referring to the drawings, the ignition switch comprises a hollow, cylindrical, die cast casing 11, the casing 11 including an insulating base 12 closing one end of the casing. Joumalled for rotation within the casing 11 is a moulded synthetic resin rotor 13, which is formed at its end remote from the base 12 with an axially extending spigot 14. The spigot 14 is provided with a non-circular bore (not shown), which in use receives a non-circular shaft coupled to the rotatable core of a key operated cylinder lock mechanism. In use the rotor 13 is driven by the core of the lock mechanism, the cylinder of the lock being defined by part of the casing of the lock mechanism.

Mounted on the rotor 13, for rotation therewith, are a pair of parallel, spaced contact arms 15, 16 respectively, the contact arms 15, 16 being positioned on diametrically opposite sides of the axis of rotation of the rotor. Further a copper contact member 17 is mounted on the rotor 13 for rotation therewith, and extends transversely to and below the contact arms l5, 16. Contact posts 18 are secured to the contact arms 15, 16 and contact posts 18a are secured to the contact member 17, compression springs 19 housed in axially extending bores 21 in the rotor urging each of the contact arms towards the contact member 17 so that the arms l5, l6 are-normally electrically connected to the member 17 by way of the contact posts 18, 18a.

The contact arms 15, 16 are each formed with an integral stepped portion 22, 23 respectively, the portions 22, 23 being at opposite ends of the respective arms. The portions 22, 23 extend parallel to their respective contact arms but are positioned closer to the base 12 then their respective contact arms so as to be urged into contact with the base 12 by the compression springs 19. The contact member 17 is also formed at one end thereof with an integral stepped portion 24, the stepped portion 24 being positioned closer to the base 12 than the contact member 17 and being urged into contact with the base by a compression spring 25 mounted in an axially extending bore 25a in the rotor. The ends of the contact arms 15, 16 remote from the portions 22, 23 are provided with integral, outwardly extending carn followers 26, 27 respectively which engage a peripheral cam track 28 formed on the base 12, the arrangement being such that the cam followers 26, 27 follow the profile of the cam track 28 as the rotor 13 is rotated.

The portions 22, 23 of the contact arms 15, 16 respectively and the portion 24 of the contact member 17 define movable contacts carried by the rotor. The base 12 carries four angularly spaced fixed contacts 29, 31, 32, 33 respectively, the fixed contacts 31, 32, 33 lying on the irnaginery circle described by the portions 22, 23 of the movable contact arms when the rotor 13 is rotated through 360, and the fixed contact 29 lying on the imaginary circle described by the portion 24 of the movable contact member when the rotor 13 is rotated through 360. The base 12 carries a further fixed contact 34 and a projection 35 on the contact member 17 is urged into engagement with the fixed contact 34 by a compression spring 36 extending between the rotor 13 and the contact member 17. The fixed contact 34 and the projection 35 both lie on the axis of rotation of the rotor 13 so that the contact 34 and projection 35 are in engagement in all angular positions of the rotor.

As was previously stated the ignition switch is intended to be combined with a steering column lock for a road vehicle and in one practical embodiment the switch is used in an ignition system incorporating a preengaged starter motor. A pre-engaged starter motor is a starter motor wherein the pinion is moved into engagement with the toothed wheel before the motor is energized at full power. In this one practical embodiment the fixed contact 29 is connected in the ignition circuit of the vehicle, the fixed contact 31 is connected in the accessories circuit of the vehicle, the fixed contacts 32 and 33 are connected in the starter motor circuit of the vehicle and the fixed contact 34 is the supply terminal of the ignition switch. Thus the projection 35 on the contact member 17 is permanently connected to the supply terminal 34. Hence the portions 22, 23 and the contact arms l5, 16 respectively, and the portion 24 and the contact member 17 serve to make electrical connections between the fixed contacts 29, 31, 32, 33 and the supply terminal 34 in the appropriate angular positions of the rotor 13. Detent means (not shown) are provided between the rotor 13 and the casing 11 to releasably retain the rotor in certain of the angular positions of the switch.

In the first position of the switch (FIG. 4a) the steering column of the road vehicle is locked, and the electrical circuits controlled by the switch are deenergized. In addition the cam followers 26, 27 are each engaged with a projection on the cam track 28 whereby each of the contact arms 15, 16 is urged away from the contact member 17 so that the contact posts 18 are spaced from the contact posts 18a.

The second position (FIG. 4b) of the switch is reached by driving the core of the key operable steering column lock so as to rotate the rotor 13 through 60 in a clockwise direction from the first position. The arrangement is such that the 60 clockwise rotation of the core of the lock is sufficient to release the steering column lock. During movement of the switch from the first position to the second position the portion 22 of the contact arm 15 engages the fixed contact 31, the cam follower 26 remaining engaged with a projection on the cam track 28 until the switch reaches its second position when the cam follower 26 becomes engaged in a depression on the cam track 28 so that the contact post 18 on the arm 15 is urged into engagement with the associated contact post 18a. Thus a circuit from the supply terminal 34 of the switch through the contact member 17 and by way of the contact posts 18a, 18 through the contact arm 15 to the fixed contact 31 is completed and the accessories circuit of the vehicle is energized. The cam follower 27 remains engaged on a projection on the cam track 28 in the second position of the switch so that the contact post 18 on the arm 16 is held spaced from its associated contact post 18a and the contact arm 16 is electrically disconnected from the supply terminal 34.

The third position (FIG. 40) of the switch is reached by rotating the rotor 13 through a further 30 in a clockwise direction from the second position. In the third position the cam follower 26 is still engaged in a depression in the cam track 28 and the portion 22 of the contact arm 15 is still engaged with the fixed contact 31 on the base 12, it being appreciated that the length of the fixed contact 31 is sufficient to accomodate the movement of the portion 22 corresponding to the 30 rotation of the rotor. Further the portion 24 of the contact member 17 is now engaged with the fixed contact 29. Thus the contact arm 15 and the contact member 17 complete the electrical circuits between the supply terminal 34 and the accessory and ignition contacts 31, 29 respectively. Also in this position of the switch the cam follower 27 is still engaged on a projection on the cam track 28 so that the contact arm 16 remains electrically disconnected from the supply terminal 34.

The fourth position (FIG. 4d) of the switch is reached by rotation of the rotor 13 through 15 in a clockwise direction from the third position. The portion 22 of the contact arm 15 is thereby moved out of engagement with the fixed contact 31 and into engagement with the fixed contact 32. However when the rotor is moved to the fourth position the cam follower 26 is moved onto a projection on the cam track 28 so that the end of the contact arm 15 adjacent the cam follower 26 is moved upwardly and the contact post 18 on the arm 15 is moved away from its respective contact post 180 to break the electrical connection between the contact arm 15 and the contact member 17. Thus the electrical circuit between supply terminal 34 and the starter motor contact 32 remains deenergized in the fourth position of the switch. However the portion 24 of the contact member 17 is still in engagement with the ignition contact 29 so that the ignition circuit is completed. During movement of the switch from the third to the fourth position the portion 23 of the contact arm 16 engages the fixed contact 33, the cam follower 27 remaining on a projection in the cam track 28 until the switch reaches its fourth position when the cam follower 27 engages a depression on the cam track so that the contact post 18 on the arm 16 is urged into engagement with its respective contact post 18a. Thus a circuit between the supply terminal 34 and the starter motor contact 33 is completed by way of the contact posts 18, 18a. When the starter motor contact 33 is closed the solenoid of the starter motor is energized and the pinion is moved towards the toothed wheel, although the starter motor is not, at this stage, operated at full power to start the engine of the road vehicle.

The fifth position of the switch (FIG. 4e) is reached by rotation of the rotor through 15 in a clockwise direction from the fourth position. In this position the portion 24 of the contact member 17 is still in engagement with the fixed contact 29, so that the electrical circuit between the supply terminal 34 and the fixed contact 29 is completed and the ignition circuit of the vehicle is energized. Also the portion 23 of the contact arm 16 is still in engagement with the fixed contact 33 and the cam follower 27 is still positioned in a depression in the cam track 30, so that the electrical circuit between the supply terminal 34 and the starter motor contact 33 is energized. Further, during movement of the switch from the fourth to the fifth position the portion 22 of the contact arm 15 remains engaged with the fixed contact 32, and when the switch reaches its fifth position the cam follower 26 is moved into a depression in the cam track 30 so that the contact post 18 on the arm 15 is urged into engagement with its respective contact post 18a and the circuit between the supply terminal 34 and the starter motor contact 32 is completed. The arrangement is such that when the contact 33 and 32 of the starter motor are closed the starter motor is operated at full power, it being appreciated that the time taken to turn the rotor from the fourth position to the fifth position is sufiicient to allow the pinion to move into full engagement with the toothed wheel of the motor.

The detent means acting between the rotor 13 and the casing 11 does not restrain the rotor in its fourth position or its fifth position and moreover spring means is provided to urge the rotor anti-clockwise from the fourth and fifth positions. Thus when the rotor 14 is released from either the fourth or fifth position, wherein the starter motor circuit of the vehicle is energized, the rotor is urged back to its third position, whereby the starter motor circuit is de-energized and the ignition and accessory circuits are completed. Further latch means (not shown) is operable on the rotor 14 so that when the rotor has been moved from the third position to either the fourth or fifth positions and then has returned to the third position, the rotor cannot immediately be moved again to its fourth or fifth position, without first being returned to its second position. Thus the latch means acts as a safety measure to prevent energization of the starter while the engine is running.

It is to be noted that as the rotor 13 is rotated and the cam followers 26, 27 follow the profile of the cam track 28, movement of each of the cam followers, 26, 27

- between a depression and an adjacent projection on the cam track causes the contact posts 18 on the contact arms 15, 16 to move in and out of engagement with the contact posts 18a on the contact member 17. In this way the making and breaking of the electrical circuits between the supply terminal 34 and the fixed contacts 31, 32 and 33 in the various angular positions of the rotor 13 is effected through the contact posts 18, 18a. Thus any arcing that may occur when said electrical circuits are made and broken is limited to between the contact posts 18, 18a and hence to ensure a long switch life it is only necessary to form the contact posts of a material which is resistant to oxidation by arcing. The contact arms 15, 16 can then be formed of a material which is less resistant to oxidation and hence need be less expensive. In the above example the contact arms 15, 16 are actually formed of brass whereas the contact posts 18, 18a are formed of silver. The making and breaking of the electrical circuit between the supply terminal 34 and the fixed contact 29 in the various switch positions is, of course, effected through the portion 24 of the copper contact member 17.

I claim:

1. An ignition switch for use in combination with a key-operated steering column lock for a road vehicle, the switch comprising a casing, a base at one end of the casing, a plurality of fixed contacts on the base, a rotor rotatable within the casing, a movable contact member mounted on the rotor for rotation therewith, first and second movable contact arms carried by the rotor and engageable with the contact member, the first and second contact arms and the contact member defining movable contacts engageable with certain of said fixed contacts in predetermined angular positions of the rotor, and co-operating cam means on the casing and said first and second contact arms, said cam means controlling engagement of the first and second contact arms with the contact member during rotation of the rotor relative to the casing, whereby when the rotor is moved into each of said predetermined angular positions at least one of said contact arms engages said contact member so that an electrical circuit between certain of said fixed contacts is completed by way of said contact member and said at least one contact arm.

2. An ignition switch as claimed in claim 1 wherein each of said movable contact arms is provided with a contact post and further contact posts are provided on said contact member, said contact arms being engageable with said contact member through said contact posts and said further contact posts respectively.

3. An ignition switch as claimed in claim 1 wherein said contact arms are resiliently urged towards said contact member. 

1. An ignition switch for use in combination with a key-operated steering column lock for a road vehicle, the switch comprising a casing, a base at one end of the casing, a plurality of fixed contacts on The base, a rotor rotatable within the casing, a movable contact member mounted on the rotor for rotation therewith, first and second movable contact arms carried by the rotor and engageable with the contact member, the first and second contact arms and the contact member defining movable contacts engageable with certain of said fixed contacts in predetermined angular positions of the rotor, and co-operating cam means on the casing and said first and second contact arms, said cam means controlling engagement of the first and second contact arms with the contact member during rotation of the rotor relative to the casing, whereby when the rotor is moved into each of said predetermined angular positions at least one of said contact arms engages said contact member so that an electrical circuit between certain of said fixed contacts is completed by way of said contact member and said at least one contact arm.
 2. An ignition switch as claimed in claim 1 wherein each of said movable contact arms is provided with a contact post and further contact posts are provided on said contact member, said contact arms being engageable with said contact member through said contact posts and said further contact posts respectively.
 3. An ignition switch as claimed in claim 1 wherein said contact arms are resiliently urged towards said contact member. 